Air conditioning systems are commonly equipped with a drain pan below the evaporator coils. The drain pan is placed below the evaporator coils to collect condensate formed by humid air contacting the cold temperatures of the air conditioning system's evaporator coils. The drain pan collects the condensate and directs it to a sewer system or an outside area through a drain line.
It is not uncommon for the drain line from the drain pan to clog due to algae or fungus growing in those lines or from other debris. Blockage of a drain line can result in condensate spilling over the drain pan and causing water damage to the surrounding area.
Typically, to correct clogging or blockage problems, the service attendant has had to cut the drain line or disconnect it from the drain pan. Through a difficult procedure, the drain line could then be cleared by applying pressure to the line. One problem with this procedure is that when cutting or disconnecting a blocked drain line there was always the potential of spillage from the drain line. Additionally, after the drain line had been cut and the blockage cleared, a repair or partial replacement of the drain line is required.
One attempt to address the problem of clearing and cleaning air conditioning drain lines was disclosed in U.S. Pat. No. 5,085,244. The assembly disclosed in this patent included a valve mechanism to which a first T-connector was joined on the upstream side of a valve mechanism and a second T-connector was joined on the downstream side. The T-connectors had engagement means for attaching pressure or vacuum sources. When a drain line in which this assembly had been installed became blocked, the valve mechanism would be closed and a pressure or vacuum source would be attached to the T-connector corresponding to the portion of drain line which was thought to be blocked.
An attempt to address the more general problem of cleaning pipes was disclosed in U.S. Pat. No. 1,274,103. This patent disclosed a valve device which had a cylindrical valve plug which did not obstruct pipe flow in its normal position but could be rotated to block the pipe either upstream or downstream of the valve. The valve plug had an axial bore from the top of the valve plug which allowed live steam or air to be injected through the valve and into the portion of the pipe which was not blocked by the valve. The disclosed valve device includes a non-removable valve stem and was built to provide an oil tight seal during service and was intended only for removing blockages from pipes by using positive pressure from steam or air.